Importance

Loading Importance Indicators...

Abstract

A protective relay communication interface includes a transformer having primary windings arranged as, at least two, sets of opposed windings. The interface is connected to a local relay sensing a current at that point on a power line to be protected. The interface is also connected to a communication link to a remote relay sensing the current at a remote position on the power line. It is by this communication link that signals representative of the sensed currents are transmitted from each relay to the other. A local signal from the local relay is passed through part of, but not all of, the primary windings inducing a corresponding signal in the secondary windings of the transformer which is transmitted to the remote relay via the communications link. A received remote signal from the remote relay is passed via at least two mutually opposed sets of the primary windings to the local relay. Because the windings are opposed, the fluxes produced cancel inducing no net current in the secondary windings of the transformer, hence preventing feedback.

Loading the Abstract Image...

First Claim